Guatemala's former president has appeared in court after spending his first night in prison.

64-year-old Otto Perez Molina, denied allegations that he was the mastermind of a customs corruption scheme dubbed La Linea, or The Line.  100 other individuals are being probed over the scheme.

A judge in Guatemala City ordered his detention on Thursday while hearings over the corruption allegations took place.

After Friday's second day of hearings, Mr Perez Molina was again taken from court to a military prison in the capita.

He denied taking any bribes and promised to co-operate with the investigation.

"Your honour, I am not going to risk my dignity, my work, nor all the effort I have made for Guatemala in return for $800,000,'' he said, in reference to the amount prosecutors say he received illegally.

Investigators say the scheme involved businesses paying bribes to government officials and customs officers in return for being allowed to evade import duties.

Mr Perez Molina reminded the court that he had rejected much higher bribe offers from the fugitive Mexican drug lord, Joaquin "Shorty" Guzman in 1993.

Mr Perez Molina led the operation that led to his arrest in Guatemala.

"After his capture, I was offered 10, 15 times more than that amount in bribes [to let him go]. I didn't do it because that goes against my principles," he said.

Guatemala's Congress stripped Mr Perez Molina of his immunity from prosecution on Tuesday and that paved way for criminal charges to be brought against him.

The vice-president was sworn in as interim head of state ahead of elections this Sunday after Mr Perez Molina resigned on Thursday. Alejandro Maldonado is expected to govern until the new president is sworn in on 14 January.

Guatemalans go to the polls on Sunday to take part in scheduled general elections as Mr Perez Molina is constitutionally barred from seeking re-election.

Mr Maldonado had only been in the post of vice-president since mid-May, when his predecessor Roxana Baldetti resigned.

Ms Baldetti is accused of involvement in the same corruption scheme that Mr Perez Molina is said to have masterminded. She is also being held in prison.

Mr Perez Molina's resignation on Thursday and arrest are a huge victory for an unprecedented anti-corruption protest movement that had swelled in recent months, with regular marches in Guatemala's major cities.