SEOUL (Reuters) -South Korea's special prosecutor asked a court on Tuesday to issue an arrest warrant for former President Yoon Suk Yeol, an investigator said, marking an intensifying investigation of the ousted leader over his botched bid to impose martial law.

Yoon, who is already facing a criminal trial on insurrection charges for leading the martial law declaration, was arrested in January after resisting authorities trying to take him into custody, but was released after 52 days on technical grounds.

The martial law attempt shocked a country that had prided itself on being a thriving democracy after overcoming military dictatorship in the 1980s and triggered a snap presidential election to pick Yoon's successor amid bitter political infighting.

The new warrant is on a charge of obstruction, a senior member of the special prosecutor's team of investigators said.

Yoon had refused to respond to summons for questioning as required under criminal procedures and investigators would "not get dragged around" by him, Park Ji-young, a deputy to the special prosecutor, told a televised briefing on YTN TV.

Yoon had been under investigation by the police and the state prosecutors' office on a number of charges stemming from the failed attempt in December to impose military rule.

A lawyer who has represented Yoon during his impeachment and criminal trials did not immediately respond to a request for comment.

In January, Yoon initially resisted an attempt by investigators trying to execute a court warrant for his arrest, holed up in the presidential residence while his security service led by officials loyal to him barricaded the gates.

The special prosecutor was appointed just days after liberal President Lee Jae-myung took office on June 4 after winning the snap election called after Yoon's ouster in April and has launched a team of more than 200 prosecutors and investigators to take over ongoing investigations against Yoon.

Yoon is fighting the charges against him that include masterminding insurrection, which is punishable by death or life in prison, claiming he had declared martial law on December 3 to sound the alarm over the threat to democracy posed by then-opposition Democratic Party.

(Reporting by Joyce Lee, Jack Kim, Ju-min ParkEditing by Ed Davies)