A mother of four is facing up to five years in a Thai prison after allegedly stealing a bar mat from an Aussie-theme bar in Phuket.

Annice Smoel, 36, of Montrose in Melbourne's outer east, says she spent two nights in a four-by-four-metre jail with three other inmates before being released on bail.

Annice Smoel says the bar mat 'theft' was a prank. Credit:3AW

She says she was arrested by undercover police on May 3 after leaving the Aussie Bar.

"I get very scared when I see police. I'm just trying to keep it together, so I can get home," she said.