A Seoul court has denied a police request to access mobile phones used by late Seoul Mayor Park Won-soon as part of their ongoing probe to determine the exact cause of his death, police said Friday.

Police had filed a request to acquire the call history for three mobile phones under Park's name, including his official phone that was retrieved when Park was found dead at a Seoul mountain last week.

The Seoul Northern District Court said while phone access can be granted in criminal investigations, there was "a lack of explanation for a mandatory probe" in this case. There was no explanation of whether the cause of his death was related to a crime, such as murder, it added.

Park is suspected of taking his own life. Police said there were no signs of foul play and the city government released a handwritten note by Park, which said that he was "sorry" to everyone, without elaborating.

Park's abrupt death came a day after a former secretary filled a complaint with the police about his alleged sexual harassment.

Civic groups and a lawyer representing the victim claimed that the public servant suffered unwanted physical contact and received inappropriate messages from Park for over four years.

Police reportedly have secured part of his call history for the day of his death and the previous day. An official said police plan to probe people with whom he talked to determine the exact cause of his death.

Investigators have been stepping up their probe surrounding the case, questioning former and incumbent officials, including Park's former chief secretary, at the city government.

The Seoul Metropolitan Police Agency said Friday it has appointed its deputy commissioner, the agency's second-highest ranking official, to lead its task force on looking into the case.

"It's a measure aimed at carrying out a swift probe with a large-scale team on (probing) whether city officials ignored (requests for help) and to prevent secondary victimization," the police said.

Separately, the city government has said it plans to form an independent investigative committee, involving women's rights groups, human rights organizations and legal experts, to probe the sexual harassment allegations raised against the three-term mayor.

But the civic groups representing the victim have raised doubt over the probe, saying the municipal government appears "to not have (the power) to get down to the truth of the case nor the will to do so" in a statement released Thursday.

In a text message to reporters following the statement release, the city government said it plans to "accept the (civic groups') request in full breadth" in forming the committee and opening the probe.

In addition to the police probe and the city's investigative committee, other groups have also filed complaints for the case, which is widely seen as a typical instance of workplace sexual harassment involving a disparity in power.

The groups have filed complaints with the police and the national human rights commission, asking authorities to probe allegations that city officials turned a blind eye to the victim's request for help and that her rights were neglected through the incident. (Yonhap)