The Delhi High Court Monday sought to know as to why the separate pleas of arms dealer Sanjay Bhandari and Robert Vadra, seeking quashing of a money laundering case against them, not be heard together.

Presently, Bhandari and his wife's petition for quashing of the ED case is being heard by a single judge, while Vadra and his close aide Manoj Arora's pleas are pending before a division bench of the high court.

Justice Mukta Gupta, who was hearing Bhandari's plea, said when these are connected matters, propriety demands that they should be heard together by the division bench.

"They are in the same ECIR (enforcement case information report). When these matters are connected, propriety and judicial principle demand that these pleas should go to the division bench," the court said.

The court was hearing an application by the Enforcement Directorate (ED) that Bhandari's plea seeking quashing of the money laundering case be transferred to the bench which is hearing Vadra's petition in the same matter.

The plea was opposed by senior advocate Sandeep Sethi, who was representing Bhandari, saying it should be heard by the single judge as Vadra has challenged the vires of the provisions of Prevention of Money Laundering Act (PMLA) but Bhandari has not done so.

The counsel said Bhandari's matter need not be transferred to the division bench and added that he would address the court in detail on this issue.

The court listed the matter for further hearing on August 23.

Vadra and Arora have sought quashing of the money laundering case against them besides challenging the Constitutionality of PMLA.

Bhandari and his wife Sonia Bhandari have moved separate pleas seeking quashing of the money laundering case lodged against them by ED in February 2017.

Bhandari, who is also an accused in a 2016 case under the Official Secrets Act relating to the recovery of confidential documents of the Ministry of Defence from his residence during an Income Tax raid in 2016, was declared a proclaimed offender by a trial court here in January last year.

He is also facing prosecution under provisions of the Black Money (Undisclosed Foreign Income and Assets) and Imposition of Tax Act, 2015.

During the probe, the ED had found that he allegedly helped Vadra, brother-in-law of Congress leader Rahul Gandhi, in purchasing a property in the United Kingdom.

The ED has lodged a money laundering case against Vadra and Arora accusing them of acquiring the London property in an illegal manner.

The ED case relates to allegations of money laundering in the purchase of a London-based property at 12, Bryanston Square, worth 1.9 million pounds. The property is allegedly owned by Vadra.

The case is before a trial court here which has granted anticipatory bail to Vadra.

In his plea before the division bench, Vadra has sought that various provisions of the PMLA, including its power to arrest and the burden of proof, be declared unconstitutional.

He has said that while it is permissible for the investigating agencies to conduct further probe, the sweeping investigation power does not warrant subjecting a citizen each time to a fresh investigation in respect of the same incident giving rise to one or more cognisable offences.

The plea has said that multiple investigations have been held in "abuse of statutory power of investigation and therefore second or successive FIRs filed in connection with the same or connected cognisable offence alleged to have been committed in the course of the same transaction pursuant to the first FIR is liable to be quashed".

The ED has raised preliminary objection on Vadra's plea saying it was not maintainable as he "wilfully suppressed" material facts from the court and it was an abuse of process of law.