After seeing their "bread-and-butter" margins squeezed by cooling measures, some real estate agents are also seeing the icing on the cake disappear.

Agents, who used to make money on the side by dabbling in property investments themselves, now find this an uphill battle.

This is, admittedly, a small proportion of the agent population, which according to the Council for Estate Agencies stood at 31,040 registered salespersons, as at Jan 1.

One agent told BT that the number of agents who invest in local properties could constitute about 3 per cent of the total number of buyers.

"In a pool of about 200 to 300 buyers for a local development, agents may constitute about 3 per cent. For overseas projects, say a good weekend where you have maybe 10 to 20 buyers, agents can make up about 20 per cent. But that's because the plate is smaller," he said.

Such investments could take place in the form of single buyers, or a group of buyers coming together to take a loan and purchase a property under one person's name.

A separate legal agreement would then be drawn up among the various parties to decide how the loan and ownership are split.

Another common gambit during the en bloc fever involved agents buying into developments on the cusp of triggering an en bloc sale, said another agent.

"If the en bloc sale goes through they would get the windfall. On the other hand, if they sense a problem they can sell the properties at a profit to the next buyer," he said.

"They usually worked as a team and got someone to broker the deal on their behalf," he said. "The holding period is usually less than a year."

The various rounds of cooling measures aimed at the property market have made such wheeling and dealing increasingly difficult, however.

The Total Debt Servicing Ratio framework which was introduced in June, for instance, not only requires "guarantors" who are standing guarantee for borrowers to be brought in as co-borrowers, it also imposes a 30 per cent haircut on the variable income component, thus limiting the ability of agents to take on property loans.