Dame Judi Dench has spoken about her grief after the death of her close friend, fellow Dame Maggie Smith, who passed away last week.

The star was asked about Dame Maggie on stage during the Cheltenham Literature Festival by fellow actor Brendan O'Hea.

O'Hea also mentioned the death of Dame Judi's husband, the actor Michael Williams, and then asked her what she had meant when she had once compared grief to petrol.

"I suppose because the energy that's created by grief...," she replied, before cutting her answer short, apparently lost for words.

Smith, best known for the Harry Potter films and Downton Abbey, was hailed as "a true legend" of stage and screen following her death at the age of 89.

Tributes were paid by King Charles III and the prime minister, as well as numerous co-stars from her long career.

The two veteran stars were the same age and had known each other for decades.

They had performed together on numerous occasions, including in the 2004 drama Ladies in Lavender.

Both starred in The Second Best Exotic Marigold Hotel in 2015, a comedy-drama that was a sequel to the 2011 hit film.

They also appeared in 2018 documentary Nothing Like a Dame, in which they playfully reminisced about their lives and careers.

The interview on Saturday covered a wide range of topics, including Dame Judi's life as an actress.

Towards the end of the session, O'Hea hesitated before saying: “I know I probably shouldn’t bring this up, I know the last week has been tricky for you because you lost your great friends Maggie Smith and Barbara Leigh-Hunt."

Leigh-Hunt, an Olivier Award-winning actress, died last month at the age of 88. She and Dame Judi had appeared alongside each other in the 1992 BBC sitcom As Time Goes By.

O'Hea then brought up a previous explanation that Dame Judi had given, of how she copes with loved ones dying.

In a past interview with The Times, when discussing the aftermath of her husband's death, she said: "Sometimes you have to do a play and it is really painful. That said, I've also found it unbelievably cathartic.

"You fortify yourself and use what you are going through as energy. Like petrol. It has helped me cope with the pain."

O'Hea questioned her on that, asking: "You say that grief can act as petrol, what do you mean by that?"

Dench didn't directly comment on either Smith or Leigh-Hunt, or her husband who died in 2001. But after mentioning her grief, she trailed off.

"It's tricky. It's tricky," O'Hea jumped in.

Dench went on to talk about the trees she plants at her home in Surrey, in memory of her loved ones who have died.

She also laughed about how some of the trees grow to resemble the person they're in honour of, while one of them, dedicated to the late actor Bob Peck, "won't grow".

Dame Maggie was known for her sharp tongue on screen and off during a varied and acclaimed career that spanned eight decades.

In the Harry Potter films, she played the acerbic Professor Minerva McGonagall, famous for her pointed witch's hat and stern manner with the young wizards at Hogwarts.

Paying tribute, Daniel Radcliffe - who played the boy wizard - said: "She was a fierce intellect, had a gloriously sharp tongue, could intimidate and charm in the same instant and was, as everyone will tell you, extremely funny."

In hit ITV drama Downton Abbey, Smith played Violet Crawley, the Dowager Countess of Grantham, the grand matriarch who excelled at withering one-liners through the show's six series.

Elsewhere in her career, she won two Oscars - for The Prime of Miss Jean Brodie in 1970 and California Suite in 1979.

She had four other nominations, and received seven Bafta awards.

King Charles described her as "a national treasure", while Sir Keir Starmer said she was "beloved by so many for her great talent".