The on and off inquiry into the Grayston Drive pedestrian and cyclist bridge that collapsed and killed two people and injured 19 others last year is set to resume, the Department of Labour said on Friday.

The inquiry, which was set up after the 14 October 2015 collapse of the temporary bridge structure across the M1 near the Grayston Drive off ramp in Johannesburg, has been deferred several times.

Department of Labour Director and Media Liaison Mokgadi Pela said the inquiry would resume next week Thursday.

"The next sitting of the M1/Grayston Drive Pedestrian and cyclist structural bridge collapse inquiry is expected to start on Thursday (07 July 2016) with testimony from construction firm, Murray & Roberts," said Pela in a statement on Friday.

He said the sitting was expected to continue for seven successive days, except on weekends, until 15 July 2016.

The Section 32 Inquiry, which was set up by the Department of Labour after the collapse of the temporary bridge structure in terms of Occupational Health and Safety, will investigate instances of alleged negligence.

"The Commission’s mandate will focus on: the responsibility of the principal constructor in terms of the construction regulations, the responsibility of the client, the responsibility of the agent on behalf of the client in terms of the same regulations, supplier of the materials and design(er)," said Pela.

The inquiry will be presided over by Lennie Samuel.

Pela said some of the interested role players and witnesses that were expected to testify include engineers, construction firm Murray & Roberts, the City of Johannesburg, the Johannesburg Development Agency, Royal HaskoningDHV, Formscaff, Engineering Council of South Africa, and the National Union of Mineworkers.

The Inquiry will be held at the Department of Labour offices (Labour Centre) at Concillium Building, Nana Sita (formerly Skinner Steet) and Thabo Sehume (Andries Street) in Pretoria/Tshwane.