Search efforts to find Malaysia Airlines flight MH370 have come under attack from a French salvage expert, provoking a fierce response from the Australian Transport Safety Bureau (ATSB).
Former French naval officer Paul-Henry Nargeolet, who worked on the recovery of the Air France flight 447, has described the project as "botched" and questioned Fugro's expertise for the AUD60 million (USD46 million) search.
But his accusations were rebutted by Martin Dolan, chief commissioner of the ATSB.
"The opportunity to tender services of the search for MH370 was open to the international underwater search industry," said Dolan on 2 June.
"A comprehensive and exhaustive evaluation process was conducted in line with strict Australian Government procurement and probity rules."
He also pointed to the recent detection of a shipwreck as proof of the technical proficiency of the winning bidder, Netherlands-based Fugro.
"The debris in the shipwreck field was significantly smaller and therefore harder to detect than we expect to find with the MH370," said Dolan.
"We have a rigorous and thorough quality assurance programme that ensures appropriate overlap between adjacent swathes and positioning of each line as well. We are achieving very accurate and consistent results with a new state-of-the-art positioning system that gives us full confidence in the towfish position, even 9 km behind the vessel."
Bathymetry maps collected during phase 1 of the search are being used to verify the system, he added.
"By matching specific features on the seafloor, we can ensure that the positions being calculated are correct, and we do this for every single line of data collected," said Dolan.
"We also perform feature matching with the side-scan sonar data between adjacent lines to ensure sufficient overlap of data is maintained. This is also done on every line as it is collected, with any deficiencies documented and catalogued."
Fugro has been using multi-beam sonar to supplement the side-scan sonar equipment, covering the traditional 'nadir' gap directly below the towfish, said Dolan.
"The multi-beam ensures more complete coverage of the seafloor it passes over," he said.
"This is optimising our rate of progress, and is a feature that is not available on some older systems that are still in use by other organisations."
All three vessels searching for missing Malaysian flight MH370 have currently been forced by bad weather to abandon operations, say authorities.
GO Phoenix and the two Fugro vessels retrieved the towfish on 30 May as conditions in the Southern Indian Ocean prevented safe search operations.
The weather is forecast to worsen in coming days with 6 m waves swelling to 12 m, ATSB reported in its weekly update of operations.
Malaysia Airlines flight MH370 disappeared on 8 March 2014 while flying from Kuala Lumpur to Beijing.