Unions have claimed the problem could cost the telco up to $1 billion in a submission to the Estens inquiry,
Telstra MD of corporate and human resources Bill Scales claimed that in 97 percent of the cases the sealant – which caused damage to around 100,000 cable joints - is effective.
Telstra said it had budgeted $75 million over two years to rectify the problem, but said that figure could increase.
