SIOUX FALLS, S.D. (AP) - Several South Dakota groups that support the Dakota, Minnesota & Eastern Railroad expansion challenged opponents in Rochester, Minn., to stop trying to scuttle the project.

"It is time to end the planned and deliberate delays," South Dakota Farm Bureau CEO Mike Held said at a news conference on Friday.

Lisa Richardson, South Dakota Corn Growers executive director, called for an inquiry.

The criticism stems from a court filing in Wyoming accusing the opponents of secretly instructing landowners how to drag out DM&E's good-faith efforts to acquire land.

The allegation arose from e-mails sent by opposition consultants but not disclosed to the Sioux Falls-based railroad as part of the discovery process in a federal lawsuit over DM&E's condemnation proceedings against about 20 Wyoming landowners.

DM&E wants a judge to order the violators to divulge e-mail messages that should have been shared, allow computer experts to check the hard drives of those involved and impose sanctions.

South Dakota Chamber of Commerce and Industry President David Owen said the recently revealed documents show that the tactics of the Mayo Clinic and Rochester Coalition are clear.

"We can see you," he said. "We now have the e-mails."

Dennis Hanson, president of the Rochester, Minn., City Council, said if DM&E opponents in Rochester had considered delaying tactics to kill the project, that is not happening now.

"I have not been at any meetings where that has been discussed," he said. "We have been up front in working with the Surface Transportation Board and the federal government to make sure we have a place at the table."

But DM&E President Kevin Schieffer said more e-mails were exchanged by DM&E opponents after the announced purchase of the DM&E by Canadian Pacific Railway, a deal awaiting approval.

"They're just not part of the public record," he said.

Schieffer said the opposition by the Rochester Coalition and Mayo Clinic continues.

"They are still working it hard. At least their consultants are," he said.

Hanson said the Minnesota opponents' problem is with the DM&E, not South Dakota shippers.

"Our disagreement is with the railroad," he said. "We understand the need for rail traffic and the ability to haul cargo. Our dispute is with whoever owns the railroad, and we want to make sure our community is protected."

Instead of trying to stop rail traffic, the Rochester Coalition is negotiating with the Canadian Pacific for tunnels or overpasses where tracks cross major Rochester roads, for whistle-free crossings, fencing and soundproofing where the tracks come near the Mayo Clinic, for speed limits through Rochester, and a process for notifying public officials if the railroad carries hazardous material through town, Hanson said.

The DM&E expansion, estimated to cost $6 billion, would add and improve tracks in Wyoming, South Dakota and Minnesota so it can ship coal from Wyoming's Powder River Basin.

South Dakota Corn Growers Association President Bill Chase, a Wolsey farmer, said the DM&E expansion would greatly help agricultural shippers. But he acknowledged the anxiety for the Wyoming ranchers whose land new tracks would cross.

"We understand this isn't a happy experience," he said. "We need to treat you fair."