Lobbyists who operate in Wales should be regulated and required to register, a Plaid Cymru AM has said.
Neil McEvoy said regulation would ensure a transparent culture in the Welsh Assembly.
Jane Hutt, government business minister, said ministers never meet commercial lobbyists.
Lobbyists are people hired by a business, an organisation or a cause to advocate their case to legislators.
The AM for South Wales Central told the Senedd that lobbyists already had to register in Australia, Canada, France, the US and Westminster.
"In Wales we have nothing, and we actually need to go much further than a register," said Mr McEvoy.
"We need to know the nature of the contracts between commercial lobbying firms and their clients, so that it's clear who they are trying to represent and for what purpose."
"We can bring lobbying out into the open and ensure that there's a transparent culture in this assembly."
He said some firms voluntarily register but said the problem with it is that "we know little about what really is going on and who is influencing what decision".
Mr McEvoy said a register for lobbyists would mean it would be known who was lobbying for who, and for what.
"If a registered lobbyist met with a government minister that would be officially recorded and the purpose of that meeting would be known," he said.
Jane Hutt, government business minister, said ministers do not meet commercial lobbyists.
"They do, of course, meet many people and organisations and consider a wide range of views as part of their formulation of government policy," she said.
"But the ministerial code makes it clear that the basic facts of all such formal meetings between ministers and outside interests groups should be recorded."
Ms Hutt added that "public affairs professionals in Wales are committed to operating professionally, responsibly and transparently".
In 2013 the assembly's standards committee called for the lobbying industry to face tighter scrutiny but not a full register.
The former presiding officer Dame Rosemary Butler had written to the UK government asking for Wales to be excluded from any legislation it was planning for the sector, which was subsequently passed.
Jayne Bryant, who chairs the assembly's standards committee, said it would launch a new inquiry in the autumn term in light of the changes in Westminster and Scotland, and "to ensure we guard against any complacency".