* Turabi says no reason given for arrest, release
* Six-week detention followed criticism of elections (Adds quotes, background)
KHARTOUM, June 30 (Reuters) - Sudanese authorities on Wednesday released Islamist opposition leader Hassan al-Turabi 1-1/2 months after arresting him in Khartoum and closing his party newspaper, his family and staff said.
“Yes they have released me,” Turabi told Reuters soon after arriving back in his home, surrounded by journalists and supporters.
“There was no explanation (for the arrest or release). There was no ground for arrest. There was no legality or procedure that was followed.”
Turabi, 78, who was close to President Omar Hassan al-Bashir before a bitter power struggle and split in 1999/2000, has been in and out of jail since he formed his Popular Congress Party (PCP). He hosted al Qaeda leader Osama bin Laden in the 1990s.
Turabi’s party put up a candidate against Bashir in April’s national elections. Turabi’s later accused Bashir, leader of the dominant National Congress Party which won most of the votes in north Sudan, of rigging the ballot.
Human rights groups have accused Bashir of cracking down on journalists and activists after a brief relaxation of media restrictions in the run-up to the elections.
Turabi said he thought his criticisms of the poll may have provoked his latest detention in Khartoum’s Kober prison. “They thought it was a bad example for someone to exercise their freedom. It would encourage others.”
Armed security agents detained Turabi in his Khartoum home in mid-May then launched a dawn raid on party newspaper Rai Al- Shaab, arresting staff and seizing a print-run.
Officials from Bashir’s National Congress Party told Reuters at the time Turabi had been arrested on suspicion of directing rebel attacks in Sudan’s Darfur region.
They said articles in Rai Al-Shaab accusing Bashir of rigging the vote and reporting Iran was developing weapons in a Sudanese factory had set out to destabilise the country.
Sudan’s state Suna news agency quoted a security source saying Bashir had ordered Turabi’s release.
The late release on Wednesday came on the 21st anniversary of the night Bashir came to power in a bloodless coup, backed by Turabi’s Islamists.
PCP lawyers said Rai Al-Shaab deputy editor in chief Abu Zur al-Amin was charged with terrorism, espionage and destabilising the constitutional system after the arrests — offences that could lead to the death penalty.
Three other journalists from the paper have also since appeared in court but the judge banned reporting of the case, their lawyers said. (Reporting by Khaled Abdelaziz and Andrew Heavens; Editing by Matthew Jones)