Umno information chief Annuar Musa refused to reveal how he came to the conclusion that Bersih chairperson Maria Chin Abdullah has links with the US Central Intelligence Agency (CIA).
"I don't need to reveal that information, even if I have it," he told Malaysiakini.
Yesterday, Annuar claimed that Maria and her late husband Yunus Lebai Ali had CIA links through their work with various election monitoring groups.
The Asia Network for Free Elections (Anfrel) and the Philippines' National Movement for Free Elections (Namfrel) have rubbished Annuar's claims.
Former Bersih chairperson and Maria's lawyer Ambiga Sreenevasan also challenged Annuar to put his claims in an affidavit.
To this, Annuar replied that Ambiga was in no position to make such a demand.
In a posting on Facebook, Annuar said Maria is "no ordinary person" and her background should be reviewed more closely.
Maria was arrested on the eve of the Nov 19 Bersih 5 rally, which attracted 40,000 people in Kuala Lumpur, to demand good governance and clean elections.
Police said she is being held under the Security Offences (Special Measures) Act (Sosma), in connection with documents found in a raid on the Bersih office in Petaling Jaya on Nov 18.
Inspector-general of police Khalid Abu Bakar declined to comment on the CIA allegations, and told reporters to ask Annuar instead.
Sosma allows up to 28 days detention without trial. Maria's habeas corpus application will be heard next Tuesday in the High Court in Kuala Lumpur. - Mkini