Denise Richards says she is so grief-stricken over ex Patrick Muldoon's death she can't watch their final film

Denise Richards praised late ex Patrick Muldoon's latest performance in a soon-to-be released film they starred in together but she is not ready to watch the finished product.

The 55-year-old actress talked candidly about working with her ex, who died at 57 on April 19, on the film Dirty Hands.

She recently told Extra's Derek Hough: 'Pat came to me with the project, and anytime he and I can work together, we do.

'Our friendship had gone on for almost 40 years. So I would have worked on anything with him.'

Richards went on to say that promoting the film has been 'very difficult' due to the 'shocking' nature of his death despite her knowing that the late star would have wanted him to.

She was asked if Richards's daughters - Sami, 22, Lola, 20, and 14-year-old Eloise - have seen the film. 

Richards replied: 'I was going to watch it last weekend. I can't watch the final cut yet.'

She did say that she had seen scenes along the filming journey as she called it Muldoon's 'best performance.'

The actress talked about his bond with her kids as well.

She said: 'My daughters were so close to Pat, so they can't watch it right now.

'One day we will come back to this, but I'm grateful … I have this memory.'

The two stars had dated on and off in the 90s and had worked together on multiple films including Starship Troopers, My Adventures With Santa, and A Christmas reunion.

Richards said: 'We've reunited on so many films over the years and have been so lucky and blessed to work with each other.

'Anytime we could work together, we have. We have always loved being on set together, and there's such a respect. There's a safety with us with being able to feel vulnerable … [with] no judgment.'

Last week, Richards shared a clip from the film in a bittersweet message posted to Instagram, the 55-year-old actress said she and the late actor had planned to do press this week for their new crime-thriller Dirty Hands ahead of its release on Friday, but tragically that didn’t come to be.

Richards wrote: 'He was so passionate about this movie & worked so hard on it. He was personally close to many involved.'

She previously talked about starring together in 1997 sci-fi flick Starship Troopers.

'We did our first movie together & I am so blessed & grateful I did his last movie with him,' added Richards, whose daughter Lola Sheen shared a touching tribute to the late actor.

The movie casts Muldoon as Chicago drug runner Richie Denton and Kevin Interdonato as his younger brother Danny. The plot thickens when a routine drug deal goes wrong and leaves them on the run from rival gangs and their own boss.

Richards plays Sheila, Richie's girlfriend who finds herself torn between loyalties.

The actress shared a scene where her and Muldoon's character have a tense conversation over the phone.

'The last time you lied to me, we almost lost everything. What are we going to lose this time?' Sheila asks her lover, who answers, 'I think everything is peachy, Sheil… I'm gonna be home in a couple of hours, okay?'

Richards continued in her post, 'While I'm still in shock and devastated, I wanted to share this clip. I know he would want everyone to see the movie. His dear friend Kevin wrote & directed & acted in it & his dear friend Guy produced & acted in it.

'He was so proud of this movie,' she added.

Richards' post brought a slew of sympathetic replies, including one from her daughter Lola, who wrote, 'Ugh I love you mom I'm so so sorry. He's cheering you on from heaven.'

Muldoon suffered a heart attack at the Beverly Hills home he shared with his girlfriend Miriam Rothbart on Sunday morning, his manager confirmed to Variety.

The actor - who was best known for his roles in Days of Our Lives and Melrose Place - had gone to take a shower and was found unconscious on the bathroom floor when his girlfriend checked on him. Paramedics were called to the scene but they were unable to revive him.

Earlier this week, Richards reflected on their decades-long friendship in a heartfelt note on Instagram.

'I am deeply heartbroken and devastated losing you. You were my best friend and my family,' she wrote on Tuesday.

'We met in our first acting class, I was 19 never had an acting job and you were 21 a student at USC doing a recurring role on Who’s the Boss [sic].

'And here we are. 36 years later. My whole adult life and I don’t know it without you.'

Days before his untimely death, Muldoon shared his excitement over another upcoming project, the crime film Kockroach, which is based on William Lashner’s novel of the same name.

'So excited to be a part of this amazing project KOCKROACH directed by Matt Ross starring Chris Hemsworth, Taron Edgerton, Zazzie Beetz And Alec Baldwin [sic],' he wrote on Instagram.

Muldoon - who didn't star but was one of the executive producers - tagged Hemsworth, Egerton and Beetz and said that filming was underway in Australia.

He also uploaded a screenshot of the movie announcement before giving recognition to other fellow executive producers.

According to IMDb, the film is described as: 'A mysterious outsider rises through New York's underworld, building a criminal empire and becoming a powerful crime boss while challenging the city's established criminal hierarchy.'

Kockroach is being directed by Matt Ross and also stars Rachel Sennott and Channing Tatum.

There has been no word of production changes following Muldoon’s death.

His sister, Shana Muldoon Zappa, shared on Wednesday there will be a celebration of life ceremony, but right now the family is still processing their loss.