The 27-year-old marked both goals by apparently mimicking a pornography website's 'spy' symbol.
A statement released by a Swansea spokesman said: "As a club we were unaware of any links to the internet group in question and disappointed to learn of the association as it does not reflect the values of Swansea City nor our strong commitment to equality.
"We wholeheartedly condemn the degradation of women and believe everyone's rights, dignity and individual worth is to be respected.
"Having spoken to Sam, he was not fully aware of the pornographic sections of this internet group and at no time intended to cause offence which he apologises for.
"The club will speak to Sam again internally to establish the full facts, while also taking the opportunity to remind everyone of their responsibilities."