A manager who said union officials threatened workers at a meeting was in another building and could not have heard what was said, an inquiry has heard.

A construction manager who said he heard union officials bullying non-union workers on a worksite was in a different building three metres away from the alleged incident, the inquiry into trade unions has heard.

Nicolas Navarrete, a project manager for construction company Smithbridge Australia, testified to the Royal Commission into Trade Union Governance and Corruption that he heard an organiser from the construction union threaten workers and give them five minutes to become union members.

However, Gregg Churchman, a delegate for the Construction, Forestry, Mining and Energy Union (CFMEU) on the Gladstone Boardwalk project in Queensland, told the commission Mr Navarrete was in his office in a worksite hut three metres from the “smoko room” where the September, 2013 meeting took place.

Mr Navarrete told the commission on Wednesday he was in his office and overheard Jodie Moses, the CFMEU official accompanying Mr Churchman, threaten workers.

“I heard Moses say ‘Smithbridge employees won’t be going back to work today if you don’t sign up to the CFMEU union’,” Mr Navarette said on Thursday.

Mr Churchman told the commission the meeting was held in the smoko room with the doors and windows shut and the air-conditioning running and denied any threats were made.

“It would have been impossible, in my view, for Mr Navarrete to have overheard our conversation,” he said.

Counsel assisting the commission, Jeremy Stoljar, said Mr Churchman was accusing Mr Navarrete of lying, then accused Mr Churchman of making his evidence up.

“He (Mr Navarrete) might believe that he, himself, did hear it,” Mr Churchman said.

Earlier, a former CFMEU official denied ever banning a Queensland crane company, saying email evidence of a boycott was “concocted”.

Peter Close told the commission no ban was ever placed on Universal Cranes, a business owned by Albert Smith.

Mr Smith has testified the CFMEU banned Universal from worksites in Queensland in 2012 after he refused to sign up to a union enterprise bargaining agreement.

On Thursday Mr Close repeatedly insisted no boycott existed.

However, email records submitted by Mr Smith show exchanges from 2012 as negotiations wound on.

“I refer to our recent conversations regarding the CFMEU boycott of Universal Cranes on projects where the head contractors are prepared to support your action against us,” Mr Smith wrote on August 14, 2012.

After proposing terms of agreement, including making payments to a union-run redundancy fund, Mr Smith asks if the CFMEU will “lift its ban”.

Mr Close responded from his iPhone: “Will also want you to fix the membership if we are to move forward.”

Asked what percentage of Universal’s workforce should be union members, Mr Close replied: “Ninety per cent I reckon that’s fair for me”.

Mr Close said negotiations with Universal and Mr Smith had gone on for years and had been extremely difficult.