Ashkelon Mayor Itamar Shimoni was arrested on Tuesday on suspicion of rape and taking bribes.
Four other people were also arrested on suspicion of involvement in bribery, fraud and other criminal activities.
Shimoni is suspected of involvement in a series of sex crimes with several women.
He is also suspected of using his position of authority to coerce women into supposedly consensual sexual relations and sexual harassment.
The police also believe that he promoted the interests of contractors and developers in exchange for bribes, as well as committing fraud and money-laundering.
The arrest of Shimoni and the others followed a months-long confidential investigation.
On Tuesday morning, police raided the Ashkelon municipality and the homes of the suspects, confiscating documents, computers, furniture and accounts for the purposes of requesting a forfeiture order.
The municipality said in a statement that it was cooperating fully with the police and would provide whatever assistance was needed.
“We trust the Israel Police to do its work fairly,” said acting Mayor Efi Mor. “Work at the municipality is continuing as normal, according to the vision of the mayor and in accordance with the 2016 program that was approved by the council a month ago.
“We will continue to work ceaselessly for the people of Ashkelon, as we have done for the past two years.”
About two weeks ago, Mateh Yehuda regional council head Moshe Dadon and 11 others were arrested on suspicion of being involved in corruption. Dadon is suspected of taking bribes, obstruction of justice, fraudulent dealings, sexual offences and more.
The police suspect that construction contractors paid bribes to receive contracts for projects in the Mateh Yehuda area, which is just west of Jerusalem. One of the prime suspects is the contractor Gabriel Magnazi, who is suspected of offering bribes and fraudulent activities.