The video shows Richard Dreyfus trying on 5 dresses ahead of the anti-trans campaign

TMZ obtained surveillance footage from the end of May… showing Richard being helped by a number of employees at Worthy Girl Consignment in Beverly, Massachusetts – where he later got on stage and made a number of controversial remarks, including against trans people .

As you can see — employees are seen helping the Oscar winner try on 5 different looks… as he smiles and laughs with those in the store before finally choosing one.

We're told Richard ended up staying at the consignment store for about 30 minutes, eventually settling on the blue, floral dress he wore on stage — which our sources say is from plus-size brand Torrid and costs $20.99.

As we previously reported…the actor then took action Controversial appearance at the Cabot Theater later Saturday evening… where he stepped out wearing the dress in question before launching into a tirade about the transgender community – among other inflammatory statements.

Now, Worthy Girl Consignment is very angry… with one employee telling us that the actor's words insulted their main clients – the LGBTQ+ community, which they are shocked by.

The employee adds that they thought RD was just a cute little old man trying on dresses — and they could never have known he planned any of that.

It's interesting… Of all the stores in Beverly, Richard chose Worthy Girl Consignment… as the company made it clear that they are supportive of the LGBTQ+ community by hanging a pride flag on their storefront.

It remains unclear whether Richard realized the irony at the time or not. Anyway, we're told the store is cashing in on the controversy for a good cause, designing a pride T-shirt referencing the incident — with proceeds going to the North Shore Alliance for GLBTQ+ Youth.