Private forensic investigator Paul O'Sullivan will face more charges when he appears in court tomorrow, The Times has learned. O'Sullivan, who is investigating senior police officers for corruption, was arrested on immigration violations at the weekend.But the Hawks yesterday labelled as frivolous allegations that his arrest was because he was investigating the police."He was arrested because he allegedly violated immigration laws," said Hawks spokesman Brigadier Hangwani Mulaudzi.O'Sullivan was arrested on Friday at OR Tambo International Airport in Johannesburg.The arrest team, said Mulaudzi, investigated serious and violent crimes, including hijackings and robberies of businessmen followed from airports and banks.Asked why this team was involved in O'Sullivan's case he said police teams worked interdependently to improve security at borders."I do not know anything about any criminal case which the suspect has allegedly brought against police officers," said Mulaudzi."The suspect, who is being detained in Pretoria, will appear in court tomorrow on several charges relating to immigration offences."The matter, he said, was now being handled by the Department of Home Affairs.Home Affairs spokesman Mayihlome Tshwete said: "The suspect has multiple passports and has allegedly been using certain ones to enter the country, while leaving South Africa on others."A source with knowledge of the investigation, said the immigration violations were minor to charges he would face in court."Those behind the arrest were looking for a reason to get him behind bars. O'Sullivan unfortunately seems to have given these people the opportunity to arrest him," said the source.Gauteng Hawks head Major-General Prince Mokotedi confirmed to the Sunday Times that other criminal charges were being investigated against O'Sullivan, but declined to elaborate.O'Sullivan was moved from Pretoria Central police station to Villeria police station at the weekend after he raised concerns about his safety, said Mokotedi."We [police] are not hiding him, we are reacting only because he asked for us [to intervene]," he said.O'Sullivan's lawyer Darryl Furman could not be reached for comment...