New Delhi, July 24 - A committee probing Delhi Metro Rail Corporation's (DMRC) worst accident July 12, which left six people dead, has held that fault in the design of the metro pillar and the construction material used was responsible for the mishap.

The panel has submitted its report to DMRC managing director E. Sreedharan and the company is likely to take action by next week, officials said.

Structural engineering expert A.K. Nagpal of the Indian Institute of Technology-Delhi headed the probe team which looked into design and construction inadequacy of pillar 67.

'I think as is known, material and design deficiency were the two aspects on which we carried out the investigation,' Nagpal told a news channel here.

Asked if the team was faced with any difficulty during the probe, Nagpal said: 'The difficult part was time constraint. I think within a short time we had to do many investigations. We are satisfied with what we have finally given.'

A team of four experts including DMRC's design cell head Rajiv Kataria probed the collapse of an under-construction beam meant to support the elevated rail track connecting central Delhi to Badarpur in the south of the capital.

Although the report was due Wednesday, Kataria was dropped from the team and the report was finally given to the Metro chief Thursday evening.