Panaji, July 13 (IANS) "Certain authorities" could be delaying permission to track down witnesses abroad who could potentially nail the police-politician-drug mafia nexus in Goa allegedly linked to Home Minister Ravi Naik's son, a key investigator said Tuesday.

Chandrakant Salgaonkar, Panaji deputy superintendent of police, told reporters that the Crime Branch had applied for all the relevant permission required to visit Sweden and question whistleblower Swedish model Lucky Farmhouse, but it had not come.

"We have asked for permission. This is a matter for investigation. I will not name the authorities. We have to ask permission from certain authorities and that we have done," said Salgaonkar, adding that permission, including one from the police head of the department were just not forthcoming.

Police sources said the state home ministry was sitting on applications by the Crime Branch for nearly two months seeking various clearances required to send a police team to Sweden.

"Permission of the head of the department (director general of police) is necessary. We are going by the rules and regulations I cannot make a vague statement. You have to work within the framework of law," said Salgaonkar, who has been accused of sabotaging investigations into the drug scandal.

The probe has already resulted in the arrest of seven policemen over the last few months. Spycam videos shot by Lucky showed Israeli drug dealer Yaniv Benaim alias Atala boasting of his links to police and politicians surfaced on the internet.

An Israeli newspaper has also linked Naik's son Roy to the Israeli drug mafia in Goa, a charge the latter has flatly denied.