The US justice department has made the first arrest in connection with the Gulf of Mexico oil disaster, charging a former engineer with destroying evidence relating to the amount of oil gushing from BP's stricken well.

Two years after the 20 April 2010 explosion on the Deepwater Horizon, the justice department said it had charged Kurt Mix with obstruction of justice for allegedly deleting hundreds of text messages relating to BP's early unsuccessful efforts to plug the well.

Mix, 50, was a drilling and project engineer on the Deepwater Horizon. After the oil rig went down, he was part of the team trying to stop the leak, according to court documents.

Those efforts included top kill, the failed attempt to gum up the well with heavy drilling mud. Mix is accused of ignoring several instructions from BP to retain all information related to the well, including his texts.

However, the court documents said Mix allegedly deleted a string of more than 200 SMS messages with a BP supervisor from his iPhone. Some of those texts, later recovered by investigators, included sensitive real-time information – such as early indications that top kill was failing. At the time, top BP officials said publicly that it was "broadly proceeding according to plan."

Mix is accused of deleting another string of texts, containing about 100 messages, on 19 August 2011 – when he learned his phone was about to be examined by an outside counsel for BP.

According to an affidavit filed in his case, a team of BP scientists and engineers, including Mix, decided on 18 May 2010, nearly a month after the blowout, that a top kill could possibly work if the flow rate of oil was about 5,000 barrels per day, which was BP's estimate at the time.

Internal BP data suggested that a top kill would fail if the flow rate was 15,000 barrels per day or more.

On 24 May, BP announced that it would start the top kill two days later, and then BP CEO Tony Hayward touted that it had a 60% to 70% chance of success.

But late on 26 May, Mix texted a drilling engineering manager, "too much flowrate – over 15,000 and too large an orifice."

However, BP kept saying publicly that the effort was proceeding according to plan. On 29 May, a Saturday, BP stopped the top kill and acknowledged its failure. The next Monday, the company's stock price plunged by 15%.

If convicted, Mix faces a maximum penalty of 20 years in prison and a fine of up to $250,000 on each count.

"The department has filed initial charges in its investigation into the Deepwater Horizon disaster against an individual for allegedly deleting records relating to the amount of oil flowing from the Macondo well after the explosion that led to the devastating tragedy in the Gulf of Mexico," attorney general Eric Holder said.

He said: "The Deepwater Horizon task force is continuing its investigation into the explosion and will hold accountable those who violated the law in connection with the largest environmental disaster in US history."

In a statement, BP said it would not comment on the case but was co-operating with the justice department and other investigations into the oil spill. "BP had clear policies requiring preservation of evidence in this case and has undertaken substantial and ongoing efforts to preserve evidence," the statement said.

During his first court appearance in Houston on Tuesday, Mix told US magistrate Stephen Smith that he understood the charges against him. He was released on $100,000 bond. His next court appearance was scheduled for 3 May in New Orleans, where the case is filed. He surrendered his passport, and his travel was restricted to Texas and Louisiana.

The charges – the first against any employee connected to the oil spill – were filed two years after the 20 April 2010 explosion killed 11 men aboard the Deepwater Horizon oil rig, spewing more than 4m barrels of oil into the Gulf of Mexico.

Mix is a relatively minor character in the Gulf of Mexico oil disaster, and the charges do not relate to the crucial days and hours leading up to the blast. But legal experts said the charges could complicate BP's efforts to consign the oil disaster to the past. The oil company last week finalised a $7.8bn settlement for economic and medical claims suffered by 100,000 individuals in the Gulf.

The oil company had also been working to reach a settlement in its civil case with the federal government.

"I think the justice department is trying to send a message," said Seth Pierce, partner in the Los Angeles firm of Mitchell Silberberg and Knupp. "He is not the ultimate target in this investigation."

Jane Barrett, director of the environmental law clinic at the University of Maryland, suggested the justice department might be trying to use Mix prosecution to to put pressure on BP to settle its civil suit. "This may be the first step in trying to get co-operation in exchange for a plea bargain for this particular defendant," she said in an email. © Guardian News and Media 2012