Mine maps planted by the ICAC: Obeid

Ex-Labor minister Eddie Obeid does not appear to have the "courage" to give evidence backing up his claim the ICAC planted crucial mining maps during an investigation, a court has heard.

Obeid and his sons Moses, Paul and Eddie junior have launched legal action against the NSW corruption watchdog, its former head David Ipp, seven of its officers and Geoffrey Watson SC.

The Supreme Court heard the Obeids allege that crucial mining maps were either planted at their family office during a raid by ICAC investigators in November 2011 or were inserted in a manila folder, within an envelope during a six-day period by the watchdog in February 2012.

The Obeids allege the envelope containing the manila folder was taken out of the ICAC's property vault and left in the hands of an investigator for six days.

It was only after this, barrister for the Obeids, Robert Newlinds SC told the Supreme Court on Friday, that the map was first seen on February 28, 2012.

"It spent six days out of the vault ... the chain of custody had been broken," he told the court.

But barrister for the ICAC, Jeremy Kirk SC, challenged this claim and the Obeids' ability to prove it.

"My learned friend Mr Newlinds admitted and conceded that his clients would not have the courage to get into the box," Mr Kirk added.

If they were not to give evidence in the civil claim, Mr Kirk questioned how they could prove these very "serious allegations" and said the court should view them with a "high degree of scepticism".

He said the Obeids should also be required to articulate their case further.

The matter will return to court in December.