Thai authorities have arrested a suspect in Bangkok’s deadliest ever bomb attack, the prime minister said on Tuesday, capping 72 hours of fast-moving developments after the investigation had appeared to be stalled.

Gen Prayuth Chan-ocha, the premier who seized power in a military coup in May last year, said a foreign man had been detained in eastern Thailand close to the Cambodian border.

Speaking to reporters following a cabinet meeting, Mr Prayuth said the detainee was one of the main perpetrators behind the August 17 bombing at the Erawan shrine in the Thai capital. But he did not say whether the suspect was believed to be the young man in a yellow T-shirt caught on security cameras dumping his rucksack at the shrine shortly before the explosion.