The mouth of a suspect is sealed by police in Huizhou, Guangdong province, Nov 18, 2013. [Photo/icpress.cn]

Police in Huizhou, Guangdong province, taped the mouths of suspects during interrogation to avoid collusion, because they could not understand the suspects' dialect.

Officers at Chenjiang police station detained 23 suspects in two mahjong parlors on Saturday, the Southern Metropolis News reported.

The suspects, from Weng'an county, Guizhou province, are believed to have been involved in as string of thefts.

Zou Chaolu, a lawyer in Guangdong, said sealing their mouths is not prohibited explicitly but there may be better ways to ensure collusion did not take place.