Calcutta, April 28: Officers questioning Saradha chief Sudipta Sen have apparently come across a phrase that sounded something like “J… Ali”.

Further interrogation has made the investigators wonder if Sen had invested some of the money — the whereabouts of which have emerged as the biggest mystery in the scandal — in the Jebel Ali Free Zone in Dubai.

Jebel Ali, the business hub 35km from Dubai, offers a slew of tax benefits to investors for up to 15 years and has emerged as one of the biggest magnets for Indian business over the past few years.

The Saradha owner himself has denied having any overseas links. “I haven’t even been to Bangladesh,” a police officer quoted Sen as saying, though his dash after April 10 as a fugitive is said to have taken him to Nepal.

But physical presence is not always needed to make investments abroad. Jebel Ali is one of the world’s fastest-growing free zones, some of which do not look too closely at the source of the funds or ask uncomfortable questions.

The officers — some of whom were not initially sure if “J…. Ali” stood for a person or a place — feel after two days of questioning and inquiries that the Dubai free zone lead should be investigated.

Investigations are still at a nascent stage and such leads need not always yield a breakthrough. But the account by the officers provides an insight into how the investigation is proceeding and how it can enter territory not familiar to police.

These officers believe that at least one investment, “possibly in a property”, was made sometime in late 2011 when Saradha Realty had hit pay dirt in Bengal and was scooping up deposits at its 294 branches.

The Jebel Ali Free Zone, abbreviated as Jafza, offers several advantages: no taxation on profits or income and no foreign exchange controls or restrictions on capital movement.

Located to the south-west of Dubai, it is spread over an area of 48sqkm and houses over 6,000 companies, including over 120 of the Fortune Global 500 enterprises. It has one of the world’s busiest ports in the world’s largest man-made harbour.

“It is difficult to ascertain how Sen’s investment was exactly channelled because the transaction details of the company from its 200-plus bank accounts are yet to reach us,” said an officer. “But not all deposits were made in banks, and we are not ruling out other means of transferring money.”

“We suspect Sen had made several overseas investments. We are trying to verify our findings to understand how he utilised the funds that his agents generated from nearly 300 offices over the years,” said a senior officer of the detective department of Bidhannagar.

The officers have learnt that Sen had invested in 150 acres while taking several properties on rent for setting up offices.

“He has land in Bishnupur, Jalpaiguri, Kalyani Highway in Barrackpore, Cooch Behar. Outside Bengal, Sen bought tracts in Jharkhand and Odisha’s Balasore,” an officer said.