An official of the northern city of Leon says authorities are investigating police who arrested the man, identified as Manuel Berumen.
City spokesman Jesus Montano says Berumen's 12-hour arrest and 850-peso ($65 fine) fine for "insulting police" and arguing with the woman who complained appear to have been unjustified.
Montano said Monday there is no law against public kissing in Leon.
About a dozen couples gathered in the same spot Sunday for a public "kiss-in" to protest the arrest.
Known for its Catholic fervor, Leon hosted a visit by Pope Benedict XVI in March.