The Mad Men star and his wife, actress Lisa Rinna, dressed up as the late Sex Pistols bassist and his girlfriend Nancy Spungen for George Clooney's Casamigos Tequila Halloween Party in Beverly Hills, California on Friday (30Oct15), but the outfits didn't sit well with everyone and some critics took aim at Hamlin for wearing a red shirt with a large swastika sign - just like one Vicious wore in a 1978 photo with Spungen.
Social media users mocked the anti-Semitic imagery and on Monday (02Nov15), Hamlin and Rinna issued a joint statement on Instagram to apologise.
In the message, posted on Rinna's profile, they wrote, "We were being authentic to the characters of Sid and Nancy for our Halloween costumes. It hurt and angered many of you and we are deeply sorry for that. That was never our intention. We did not mean to offend."
The swastika symbol, which is actually rooted in ancient mysticism, was adopted as the image for Adolf Hitler's National Socialist Party, aka the Nazis, who were responsible for rounding up Jews throughout Europe during the second World War and sending them to concentration camps - and many to their deaths. The symbol has come to represent anti-Semitism ever since.