Seven employment agencies have been accused of charging 3,000 Indonesian maids excessive fees and offering them to employers at almost half the legal minimum wage. The Immigration Department investigation - the largest ever conducted - began shortly after the Sunday Morning Post revealed last May that Indonesian maids were being provided at black-market wages. It is against the law to provide or employ a maid for below the minimum wage of $3,860 per month. It is also illegal for agencies to charge the maids more than $386 for helping them find an employer. But the seven agencies had offered maids for as low as $2,000. They had also charged them service fees ranging from $6,000 to $21,000, immigration officers said yesterday. Officers raided the seven agencies on Wednesday and seized thousands of passports, employment contracts, ledgers and blank salary receipts pre-signed by the maids. The agencies have not been named pending further investigation. The women were forced to work for months without a salary in order to pay off the debt, officials said. Many of the women had no idea how much they should be charged or what the minimum wage was, officials said. 'They're desperate to come here to work. Many of them find out only after they arrive that they've been cheated,' an Immigration Department spokesman said. 'A number of them also cannot read, so they would not understand the contracts they were signing.' Employers benefited by saving as much as $44,640 for hiring a maid for two years. Eight owners and employees of the targeted agencies were taken to the Immigration Department for questioning. Six were released unconditionally. Two owners were found with equipment used to make false identification cards and were released on bail of $2,000 and $5,000 pending further investigation. One agency, found to be operating without a licence, has been shut. The others can continue doing business pending the investigation.