Dench, 84, did not defend the behavior of the actors nor reject the allegations against them, but expressed sadness at the erasure of their work.
She told the Britain's Radio Times: "What kind of agony is that? Are we going to negate ten years at the Old Vic and everything that he (Spacey) did (as artistic director) -- how wonderful he's been in all those films?
"Are we just not going to see all those films that Harvey produced? You cannot deny somebody a talent.
"You might as well never look at a Caravaggio painting. You might as well never have gone to see Noel Coward."
Caravaggio was a murderer and Coward was accused of predatory behavior, the Radio Times noted.
Dench, who has worked with Weinstein over the years on films like "Shakespeare in Love," for which she won an Oscar, called the accusations against him "horrifying" in a statement to CNN in 2017.
A representative for Dench told CNN on Tuesday that she was unavailable for interview.
Among the allegations, Weinstein is accused of raping a woman in a New York hotel room in 2013 and forcibly performing oral sex on another woman at his Manhattan apartment in 2006. Weinstein has denied all claims of non-consensual sex.
He faces five felony charges, including two counts of predatory sexual assault, one count of criminal sexual act in the first degree, and one count each of first-degree rape and third-degree rape. He has pleaded not guilty to all charges, and his trial is set to begin September 9.
Spacey is currently being tried on charges of indecent assault and battery for allegedly groping an 18-year-old busboy in July 2016 at the Club Car bar on the island of Nantucket. He entered a plea of not guilty in January.
Netflix fired Spacey in November 2017, following a CNN report in which several current and former members of the "House of Cards" production staff came forward with allegations of sexual harassment. One also accused Spacey of sexual assault.
He apologized to actor Anthony Rapp for making a pass at the then 14-year-old some 30 years ago, but said he did not recall the incident.
CNN's Jean Casarez, Chloe Melas and Aaron Cooper contributed to this report.
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