A recent speech has given a rare glimpse into the inner-workings of the Foreign Investment Review Board (FIRB).

Recent polling has shown that up to 84 per cent of Australians see foreign investment as a critical or important threat to Australia.

But in a public appearance at the Agri Investor Forum in Melbourne on Wednesday, FIRB board member Patrick Secker said much of that concern was misplaced.

Mr Secker said public debate was not a major factor in the FIRB’s decision making.

The FIRB reviews proposed deals and issues guidance to the federal treasurer.

It was originally established by the Whitlam Government in response to concern about Japanese investment.

“Today, Japan has 0.1 per cent of Australian land assets, so they really weren't a problem, but obviously politicians are answerable to the people whether you like that or not, so they make decisions based on that,” Mr Secker said.

“So now we're seeing similar output from the media about China, which is interesting because when you look at agricultural land ownership in Australia, the official figures show there is 13.4 per cent of agricultural land [by area] owned wholly or partly by foreign investors.

“But I can guarantee you that 100 per cent of that land stays in Australia. You can't pick it up and take it away.”

The UK, USA and the Netherlands own the most Australian agricultural land.

“I don't think we've got a lot to fear from foreign investment. In fact foreign investment in agricultural land has been good,” he said.

In 2015, the Federal Government introduced FIRB reforms including new fees on applications and new thresholds to trigger a FIRB review.

Mr Secker said foreign investment remained strong even after the changes.

“The facts show it hasn't had any effect on the amount of applications or the investment in Australia, because I personally was concerned about that,” he said.

“If you look at the investment from the 2014/15 financial year to the 2015/16 financial year, in agriculture it went up 25 per cent. Again, that's good news.

“Since the fees, which are arguably a bit more than user pays, FIRB has been able to expand its resources and improve the amount and type of information at its disposal.

“We didn't want more bureaucrats to slow the process down, we wanted more to speed it up.”

He said the biggest source of delays are the extensive collaboration required with authorities like the Australian Tax Office or the Australian Securities and Investment Commission.