c# xml.Load() locking file on disk causing errors

I have a simple class XmlFileHelper as follows:

public class XmlFileHelper
{
    #region Private Members

    private XmlDocument xmlDoc = new XmlDocument();
    private string xmlFilePath;

    #endregion

    #region Constructor

    public XmlFileHelper(string xmlFilePath)
    {
        this.xmlFilePath = xmlFilePath;
        xmlDoc.Load(xmlFilePath);
    }

    #endregion

    #region Public Methods

    public XmlNode SelectSingleNode(string xPathQuery)
    {
        return xmlDoc.SelectSingleNode(xPathQuery);
    }

    public string GetAttributeValueByName(XmlNode node, string attributeName)
    {
        return node.Attributes.GetNamedItem(attributeName).Value;
    }

    #endregion

    #region Public Properties

    public string XmlFilePath
    {
        get
        {
            return xmlFilePath;
        }
    }

    #endregion
}

The issue is I am getting the following error on Load:

System.IO.IOException: The process cannot access the file ''C:\CvarUAT\ReportWriterSettings.xml'' **because it is being used by another process**

this occurs when this class is used to by two running instances of a component running in parallel both attempting to load the xml file above, this is legitimate behaviour and required by the application.

I only want to read in the xml off disk once and release any reference to the file on disk and use an in memory representation from that point forward.

I would have assumed Load operates in a readonly fashion and would have no need to lock the file, what is my best way to achieve the desired result and get around this issue?

Thanks