NEW YORK (MarketWatch)—Apple Inc. may be seen as a Silicon Valley tech darling, but supplier GT Advanced Technologies has a far less rosy view.

In leaked court documents on Friday, the maker of the Sapphire screen, which was passed up for the new iPhone 6, pegged Apple AAPL, -1.16% as a bully whose tactics played a part in GT Advanced Technologies’ US:GTATQ early October bankruptcy.

The documents, which followed a request earlier last week from a judge that more information regarding their relationship be released, paint Apple as a colossal company flexing its muscles at GT Advanced when the two were negotiating a supply agreement for sapphire materials.

Apple, however, said the allegations contain “extensive, unnecessary, scandalous and defamatory statements about Apple’s alleged intent, motives and business tactics.”

The company, headed by Tim Cook, said many of GT Advanced’s statement are “gratuitous, false, and wholly irrelevant.” It pushed for several of the claims to be redacted.

“These statement are intended to vilify Apple and portray Apple as a coercive bully,” the company said in court documents. Those statements are not only untrue and harmful to Apple, the company said, but are not necessary to understand GT Advanced’s current financial condition.

GT Advanced said Apple told the company to “put on your big boys pants and accept the agreement” when it expressed concerns regarding the terms of their sapphire agreement, which it claims was “strategically structured” to benefit Apple.

These actions and Apple’s alleged unwillingness to take responsibility for cost overruns and other expenses made its operations “unsustainable,” the supplier claims, giving Apple “inordinate control” over its liquidity, operations and decision making.

The supplier said it was unable to negotiate changes to their pricing contract despite unforeseen manufacturing circumstances that it claims made it difficult to “economically produce” a product that Apple would accept.

All of this, it said, forced it to sell “every unit of sapphire material at a substantial loss,” rack up as much as $900 million in expenses and layoff 1,300 full- and part-time workers, leading to its bankruptcy on Oct. 6, according to court documents.

Meanwhile, GT Advanced admitted in a securities filing on Thursday that its sapphire business is currently being probed by the U.S. Securities and Exchange Commission. It says it is cooperating fully with authorities.