A police source told FMT the 46-year-old contractor was arrested at 10.50pm yesterday when he arrived at Penang International Airport from Thailand.

In a statement today, Timur Laut police chief Abdul Rozak Muhammad described the suspect as the alleged “mastermind” behind the attack.

He said the suspect, whom he did not name, claimed trial at the magistrates’ court in George Town this morning for the same offence as three others charged previously.

Rozak said a total of 22 people had been arrested in the course of what he said was a thorough investigation.

In the Oct 22 incident, four men attacked lawyer Beh Hong Shien, 37, outside a coffee shop on Karpal Singh Drive, beating him with an iron rod.

Three of the suspects – Koay Beng Ghee, 36, Teh Eng Tat, 36, and Ng Weng Kooi, 41 – were charged with assault with a dangerous weapon on Dec 24 and claimed trial.

The charges were framed under Section 324 of the Penal Code, which carries a penalty of up to 10 years in prison, a fine, caning or any two of these penalties, upon conviction.