The spread between Indian onshore and offshore forward rupee forex rates widened on Friday, as the local currency plunged below 82 to the dollar to a record low.

The 1-month USD/INR non-deliverable forward (NDF) was at 82.6650 by 0514 GMT. In comparison, the outright rate onshore –– derived from spot and the 1-month forward premium –– was at around 82.60.

The spot rupee declined to a record low of 82.3825 on Friday, from 81.88 in the previous session, which likely prompted the Reserve Bank of India to intervene, traders said.

"The NDF rate quoting at a premium to the onshore rate is not uncommon at times when the rupee is under extreme stress, like it is right now," a forex sales trader at a Singapore-based bank said.

"In fact, we would say the spreads have been unusually depressed this time around. We think that is the function of the RBI intervening in offshore as well."

The rupee has witnessed a swift decline after it dropped below 80, a level, traders said, the RBI was looking to protect.

The slide from 80 to current levels has came in just eleven trading sessions.

"As long as spreads remains highly positive in favour of offshore, USD/INR may get more upward push," said Anindya Banerjee, head of research, forex and interest rates at Kotak Securities.

"With offshore points driving the market, the rupee can remain under pressure. We might see higher gap up/down risk (and) outsized moves often." (Reporting by Nimesh Vora; Editing by Savio D'Souza)