A MAN who was high on drugs has been arrested after attempting to donate methamphetamine tablets to help flood victims at a relief centre, Thai officials say.

A 39-year-old man, Jakrit Mukpradab, showed up with 11 methamphetamine pills in a small plastic zip-lock bag at a donation tent in the seaside district of Sattahip in Chonburi province on Monday, saying he wanted to help fellow Thais affected by the flooding, said local district chief Pawat Lertmukda.

He said Mr Jakrit told the volunteers 60 kilometres southeast of Bangkok that they could sell the drugs and use the money to support the troubled families. Flooding that began in mid-September has killed 61 people and affected 3.6 million people across Thailand.

"Looking high, he showed the volunteers the drugs and told them, 'I don't have any money to donate. Will these do?'" Mr Pawat said.

"Little did he know that the volunteers were actually from a civil drug suppression task force."

Mr Pawat said the man said he took some methamphetamine before the incident and said he used to be a drug dealer.

Mr Jakrit was handed over to police and will face charges of narcotics possession for personal use. He could face up to 10 years' imprisonment.

Police searched his house on Monday but did not find any more drugs, but they did find an unlicenced gun and bullets.